Dietary Fat Helps Boost Vitamin D Absorption

The sunshine vitamin just found a new friend—dietary fat. A new study from Tufts University researchers has found that taking vitamin D supplements along with a meal containing fat boosts the absorption of vitamin D significantly. Published in the Journal of the Academy of Nutrition and Dietetics, the study divided 50 healthy older men and women into three groups; one group took vitamin D while consuming a fat-free breakfast, while the second and third groups took vitamin D while consuming a breakfast that was 30% fat by calories. The ratio of monounsaturated to polyunsaturated fats was 1:4 in the meal consumed by the second group, whereas that ratio of dietary fat was reversed in the meal consumed by the third group (4:1). All of the participants took a single, 50,000 IU dose of powdered vitamin D-3 with their breakfast for this one-day study. Here’s what the researchers discovered:

12 hours after taking the vitamin D supplement, participants who ate a fat-containing breakfast experienced a 32% increase in vitamin D absorption compared to those in the fat-free group.

Participants who ate a fat-containing breakfast experienced a 40% increase in vitamin D absorption after 10 hours and a 25% increase after 14 hours, compared to the fat-free group.

The absorption rates of the two groups who consumed a fat-containing breakfast did not differ significantly at any point. Hence, the ratio of monounsaturated to polyunsaturated fats did not affect vitamin D absorption.

The study sheds an important light on how diet affects vitamin D absorption—an issue that previously has not been well understood.